1. Field of the Invention
The present invention relates to an optical lens acting on light emitted from a light-emitting device, a method of manufacturing an optical lens, and a drawing optical lens preform for making an optical lens.
2. Related Background Art
Japanese Patent Publication No. 3121614 and U.K. Patent Application GB2108483A disclose methods of manufacturing a microlens by drawing. In the methods disclosed in these literatures, a columnar preform is prepared and then is drawn upon heating, whereby a columnar lens having a cross-sectional form substantially the same as that of the preform is formed.
In such a conventional method of manufacturing an optical lens, the preform may incur distortions and the like in the process of drawing, thus deforming, whereby there have been cases where an optically active part to act on incident light is not formed as designed.